1. Field of the Invention
This invention relates to novel neem bark extracts. The neem bark extracts according to the invention possess antimitotic activity in sea urchin eggs and activity against mouse L-5178Y cells and transplanted sarcoma 180 tumors.
As a result of extensive studies on pharmacological actions of constituents contained in the neem materials, it has now been found that consecutive treatments of the neem bark with two solvents of different dielectric constants result in the constituents possessing the antineoplastic activity mentioned above.
It is therefore the object of the present invention to provide neem bark extracts which are active against mouse L-5178Y cells and transplanted sarcoma 180 tumors.
2. Description of the Prior Art
It is heretofore known that neem extracts contain various pharmacologically active constituents. In fact, there are disclosed a method of producing cosmetics for the skin from the bark, leaves, flowers, fruits, branch, root epidermis or resin of neem by extracting the same with water or a hydrophilic solvent or by finely pulverizing the same (Japanese Patent Publication Nos. 28853/77, 28854/77 and 10125/78); a method of preparing from such neem materials the constituents possessing gastrointestinal and hepatic function-improving activities by extracting the same with a hydrophilic solvent and/or hot water (Japanese Patent Publication No. 10124/78); and a method of preparing from such neem materials the constituents that are effective for the therapy of dermatological and rheumatic diseases by extracting the same with a hydrophobic solvent (Japanese Patent Publication No. 13689/78). These methods are distinct from the present invention in that there are involved in order to produce the active constituents no pretreatment but direct extraction process only.